Fluidising devices



June 19, 1956 F. J. B. BERRY 2,750,681

FLUIDISING DEVICES Filed April 16, 1954 INVENTOR FRAA/cms 1/ .B. .BE'RRy United States Patent FLUIDISING DEVICES Francois Jacques Barthelemy Berry, Lille, France Application April 16, 1954, Serial No. 423,741

Claims priority, application France April 21, 1953 3 Claims. (Cl. 3457) In industrial processes, it is often required to pass through a mass of fine solid products, a flow of gas which is sufiiciently powerful to raise slightly the particles of the mass and to give them a relative movement with respect to each other so as to induce the mass to behave in a similar manner to that of aliquid. Such a fiuidisation of a mass of fine solid products, is used for example, in the gasefying of coal and also in making a layer of sand or like material suitable for the sorting of solid lumps by the density process, or in a more general manner to cause the gases to enter into contact with all the particles of the mass forexample as in the case of'catalytic processes or chemical reactions.

The usual fluidising arrangements generally consist of a box in which the mass to be fluidised is contained, and the perforated horizontal bottom of which communicates with a conduit through which the gas is supplied to the box. These known arrangements are not fully satisfactory. In particular, the gases have a tendency to escape along the Walls of the box to the detriment of the remainder of the mass, whilst pockets of gas are set up close to the bottom of the box and finally result in continuous chimneys of gas which give rise to undesirable disturbances and reduce to a considerable extent the amount of gas passing through the remainder of the mass. In any case, the distribution of the gaseous flow through the mass is irregular, and this reduces considerably both the efiiciency of the gas flow and the efiiciency of fiuidisation.

The object of the present invention is to effect improvements in fiuidisation devices which obviate the drawbacks referred to and ensure a uniform distribution of the gaseous flow through the mass to be fluidised, without giving rise to any wall effects or pockets of gas.

In accordance with an essential feature of the invention, the flow of gas admitted to the mass to be fluidised is given a pulsatory character.

The features and advantages of the invention will, furthermore, become apparent from the description which follows below of forms of embodiment chosen by way of example, with reference to the attached drawings in which:

Figs. 1, 2, 3, 4 and 5 are respectively views in vertical cross-section of various forms of construction of the fluidising box in accordance with the invention.

With reference to Fig. 1, there is shown at a box in the shape of a parallelopiped open at its upper end at 11 and consisting of vertical walls 12 and also a horizontal base 13 perforated at 14. A ventilating duct 15 is provided under the box and communicates with the whole surface area of the base 13. The duct 15 is supplied with gas under pressure having a pulsatory nature. The box 10 is filled with a mass 16 of time solid products which are retained by the holes 14. Horizontal fins 17 spaced apart one above the other throughout the entire height of the vertical walls 12 are fixed to these latter and extend into the box 10.

In operation, the flow of gas issuing from the duct 15 and passing upwards through the mass 16 by the holes 14 fluidises this said mass, by which is meant that it is 2,750,681 Patented June 19, 1956 made to behave in a manner similar to a liquid, the elementary particles having, however, a less degree of mobility.

By virtue of the pulsatory nature of the flow of gas, and of the arrangement of the fins 17, the flow of gas encounters roughly the same resistance in the vicinity of the vertical walls 12 as it does in the main body of the mass. The fiuidisation is thus approximately uniform over the whole horizontal area of the mass 16 and the efficiency of gas flow is excellent.

With reference to Fig. 2, there is shown an alternative form in which the box is still open at its upper part but is perforated not only at its base 13 with holes 19, but also over the greater portion at 20 of its vertical walls 21, which may or may not be provided with fins as shown in Fig. 1.

The ventilating duct 18, supplied with gas under pressure having a pulsatory nature, is connected to the box and communicates with the whole of the perforated surface area of the base 13 and of the walls 21.

In operation, the flow of gas passing out of the duct 18 and passing upwards into the mass 16 through the holes 19, causes this mass to be fluidised. By virtue of the pulsatory character of the flow of gas and of the arrangement of the holes 20, the gas flow which would have a tendency to escape readily along the walls 21, is opposed by the flow of gas which passes through the holes 20. The fiuidisation effect is again in this case approximately uniformly distributed over the entire horizontal surface area of the mass 16.

Referring now to Fig. 3 of the drawings, it is seen in this case that the perforated base 22 of the box with vertical walls 23 is provided, inside the box, with a cellular form of partitioning 24, for example in the shape of a honeycomb or other form, the cells of which are formed by vertical walls and are open both at the top and the bottom.

The flow of gas passing out of the duct 25 and passing through the base 22, has always a pulsatory nature and is distributed in the vicinity of the base amongst a large number of cells which have no lateral or horizontal communication between each other. Any pocket of gas which tends to be created near to the base is thus very limited in its extent and is practically eliminated.

In a further alternative form shown in Fig. 4, the duct 26 serving to supply the gas under pressure having a pulsatory nature, is fixed and connected by means of a bellows member 27 to the box 28, in such a way that the duct communicates with the perforated base of the box. The box 28 has applied to it a series of vertically-directed shocks and, for this purpose, it is carried at each side by articulated systems 30 actuated by two vertical crankarms 31. The crank-arms 31 are pivoted at 32 to cranked levers 33, the other arms 34 of which are connected together by means of a coupling arm 35. The arm 34 of one of the levers 33 is further connected by means of a driving rod 36 to an eccentric 37 mounted on a driving shaft 38.

In operation, the box 28 has imparted to it successive vertically-directed shocks in such a way that the pockets of gas which would tend to be formed in the vicinity of the base 29 are re-absorbed and disappear.

In a further modification shown in Fig. 5, in which means are shown in more detail for giving the flow of gas a pulsatory nature, the box 39, the base of which is shown at 40, has its lateral vertical wall 41 extended downwards at 42 in the form of a cylinder. A piston 43 is slidably mounted inside the cylinder 42 and comprises pivotally-mounted flap-valves 44. The piston 43 has applied to it successive shocks in a vertical direction and, for this purpose, it is carried on pivoting members 45 attached to vertical crank-arms 46. The crankazms 46=arerpivotallyattached at 47 to cranked levers 48, theother arms 49 of which areconnected .togetherby a coupling arm 50. The arm 49 of one of the levers 48 is connected to an eccentric-S2 by means of a driving rod 51,,the eccentric being mounted on-a.idriving 'shaft53.

Ateachrevolution of the shaft 53, .the piston 43-is raised, the flap-valves 44 being closed, so that the ,airis compressed beneath the base .40 and passes throughf-the mass contained in thebox, and then when the piston moves downwards, the flap-valves open so as-to admit air tO'zthS upper side of the piston. A plusatory flow (or an intermittent how) of gas passes through themass contained .inqthe boX and a flow of thisnature enables the air pockets to be eliminated, whichwould otherwisehave a-t'tendency to beset up ;in' the vicinity of the base. Any othersuitable means may be provided for giving a pulsatory nature to the flow of gasin thecase of Figs. 1, 2, 3, 4 and. 5, for example by means of the alternate opening and closing ofa damper in the delivery duct-of a fan, or by means of a volumetric fan having two rotors geared together was to give a pulsatory output.

It will, of course, be understood'that the invention is notlimited to the forms of construction described and shown, but includes in its scope all the alternatives which can .be employed in the embodiment of its various members. In particular, it is clear that the invention covers fiuidising'apparatus which results from the various possible combinations of the arrangements described and shown.

What I claim is:

1. .A device for fluidising amass of time granular solid products, said device comprising a container of .cylindricalshape, a plurality of passages formed in thebase of said container, said passages being so dimensioned that the particles of the said mass do not pass therethrough, a downwardly-projecting cylindrical portion formed by an extension of the cylindrical walls of said container below said base, a piston slidably mounted in said cylindrical extension, at least one articulated flap-valve mounted in 4 the web of said piston, a supply of gas to the underside of said. piston, and mechanical. m ans includingv at. least .0 1 articulated system for impressing an oscillating motion on said piston, whereby the gas forced through said mass is adapted to be given a pulsatory character.

2. A device as claimed in claim 1, in which the said articulated systems include at least one bell-crank lever, one arm of which is coupled to the underside of said piston, the other arm'beingcoupled to arotary eccentric driving device.

3. A device for fiuidizing a mass of fine granular solid products, said .device comprising a container, .a plurality of passages formed in the base of said container, said passages being so dimensionedthat the particles of the said mass do not pass therethrough, a downwardlyprojecting extension of the walls of said container below said base, a reciprocating element slidably mounted in said extension, at least one articulated baflle mounted in said reciprocating element, a supply ofgasto. the underside of said element, and mechanical means including ;at least one articulated system for impressing an oscillating motion on said reciprocating element, whereby the gas is moved through said reciprocating element past thebaffie and forced through said mass in a pulsatory character.

References Cited in the file of this patent UNITED STATES PATENTS 1,849,146 Kraut Mar. 15, 1932 1,971,852 Goebels Aug. 28, '1934 2,125,913 Goebels Aug. 9, 1938 2,371,619 Hartley Mar. 20, 19.45 2,445,516 Dickey July20,l9 48 2,472,873 Woodrum June 4, 1949 2,665,035 Schemm Jan. 5,1954 2,667,706 Morse et al. Feb. 2, 1954 FOREIGN PATENTS 225,734 Germany Sept. 19, 1910 

1. A DEVICE FOR FLUIDISING A MASS OF FINE GRANULAR SOLID PRODUCTS, SAID DEVICE COMPRISING A CONTAINER OF CYLINDRICAL SHAPE, A PLURALITY OF PASSAGES FORMED IN THE BASE OF SAID CONTAINER, SAID PASSAGES BEING SO DIMENSIONED THAT THE PARTICLES OF THE SAID MASS DO NOT PASS THERETHROUGH, A DOWNWARDLY-PROJECTING CYLINDRICAL PORTION FORMED BY AN EXTENSION OF THE CYLINDRICAL WALLS OF SAID CONTAINER BELOW SAID BASE, A PISTON SLIDABLY MOUNTED IN SAID CYLINDRICAL EXTENSION, AT LEAST ONE ARTICULATED FLAP-VALVE MOUNTED IN THE WEB OF SAID PISTON, A SUPPLY OF GAS TO THE UNDERSIDE OF SAID PISTON, AND MECHANICAL MEANS INCLUDING AT LEAST ONE ARTICULATED SYSTEM FOR IMPRESSING AN OSCILLATING MOTION ON SAID PISTON, WHEREBY THE GAS FORCED THROUGH SAID MASS IS ADAPTED TO BE GIVEN A PULSATORY CHARACTER. 